Reconfigurable gantry tool

ABSTRACT

The present invention is embodied in a reconfigurable gantry tool and a reconfigurable tool system. The reconfigurable tool includes a platform, a reconfigurable holding mechanism, a gantry frame, a multi-axis numerically controlled robotic tool, a multi-movement control device coupled to the mobile multi-axis tool, and a rotatable and translatable sine plate. The reconfigurable gantry tool system comprises a plurality of reconfigurable gantry tools strategically coupled to one another to form a non-matrix assembly line. Other tooling systems can be coupled to and/or within the reconfigurable gantry tool system for performing additional operations.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to gantry tools and, inparticular, to reconfigurable precision gantry tools and reconfigurabletooling systems for performing tooling operations on workpieces andassembling structures.

2. Related Art

The precision machining of large workpieces requires the use of a widearray of expensive machine tools such as full size models and gauges,templates, fixtures, drill hoods, and drill-sets. These tools have asubstantial acquisition and maintenance costs, as well as costs relatedto their storage, property management, inspection, reinspection, andaccountability. In addition, the manufacturing tolerances andrepeatability achievable with these tools is limited.

For example in the aerospace industry, large airframe components such asfuselage sections can be precision machined only with the use of verycostly full size models and gauges. A typical series of models needed todrill precision holes is shown in FIGS. 1A-2B. As shown in FIG. 1A, thefirst step in this process is to fabricate a male master model 100 of afuselage section, which model is made of metal or plaster and hasprojections 105 of the size and at the locations required for the holesto be drilled in the fuselage section. A female plaster cast 110 isformed over the model 100, which cast has apertures 115 formed over theprojections 105.

As shown in FIG. 1B, a male cast back 120 is formed from the plastercast 110, which cast back is also made from plaster. Again, projections125 are formed by the plaster flowing into the apertures 115 in the cast110 of FIG. 1A. Finally, a drill bonnet 130 made of a compositematerial, such as fiberglass or graphite composite, is formed over thecast back 120. The bonnet 130 has apertures 135 of the correct size andat the correct locations where holes are required to be drilled.

The first step in using the bonnet 130 is to fasten a fuselage sectioninto an assembly jig using bracing means, or "details", and locator pinsto provide a reference position for the fuselage. The bonnet 130 is thensecured adjacent the fuselage section and aligned with the section usingthe locator pins. The bonnet 130 then serves as a drilling templatethrough which holes are drilled into the fuselage section. It should benoted that FIGS. 1A and 1B are basic drawings and show only a few holesfor simplicity. An actual bonnet will have hundreds and possiblythousands of holes.

As such, the cost to fabricate a typical drill bonnet 130 can average $1million and take from 1 to 12 months. As an example, for the F-18aircraft, 900 bonnets are needed to drill all the fuselage holes. Thus,the total cost for the drill bonnet tool family for the F-18 isapproximately $1 billion. Full scale interior models, called mastergages, are also required to precisely locate and drill holes in detailswhich are attached to interior structures of the assembly jig. Thesedetails are used to locate bulkheads, frames and ribs of the aircraft.Such master gages can cost between $5-10 million each and the F-18requires 33 such master gages, for a total master gage tool family costof approximately $250 million. In addition, new master models and gagesneed to be fabricated for either a new aircraft component or changes toan existing one, requiring from four to 24 months to prepare.

Therefore, what is needed is a device that eliminates the need forcostly tool families, such as drill hoods, master models, gauges andfacility fixtures. What is also needed is a device that is inexpensiveand is made from standardized parts to reduce cost and fabrication time.What is also needed is a device that is reconfigurable and for customtooling operations. Further, what is needed is a device having aleveling mechanism with a programmable memory to improve accuracy ofhole location and to allow repetitive tooling operations.

Moreover, the large assembly jigs, large drill bonnets, drill tools, anddrill hoods discussed above are used to assemble an entire structure,such as an aircraft. This process is referred to as a fixed custommatrix. This is because each different workpiece, no matter how slightthe difference, must have its own custom assembly jig since the jigs arenot reconfigurable. In this painstaking and expensive process, for eachcustom jig, tooling operations are performed only one workpiece at atime. Expensive work stands are elevated above the ground and are builtaround each custom assembly jig to allow workers to perform toolingoperations on the workpiece. As a result, the expensive custom assemblyjigs are the building blocks of the structure to be built. Consequently,this technique is very expensive, inefficient, and wastes resources.

Therefore, what is needed is an apparatus and method for assemblinglarge structures without fixed custom matrices. What is additionallyneeded is a new assembly line with reconfigurable tools for assemblinglarge structures. What is further needed is a new assembly line whichuses the workpieces that comprise the final structure as the buildingblocks of the final structure and not the custom assembly jigs.

Whatever the merits of the above mentioned systems and methods, they donot achieve the benefits of the present invention.

SUMMARY OF THE INVENTION

To overcome the limitations in the prior art described above, and toovercome other limitations that will become apparent upon reading andunderstanding the present specification, the present invention isembodied in a reconfigurable gantry tool and a reconfigurable toolsystem. The reconfigurable tool includes a platform, a reconfigurableholding mechanism, a gantry frame, a multi-axis numerically controlledrobotic tool, a multi-movement control device coupled to the mobilemulti-axis tool, and a rotatable and translatable sine plate.

In one embodiment of the present invention, the reconfigurable gantrytool system comprises a plurality of reconfigurable gantry toolsstrategically coupled to one another to form a non-matrix assembly line.Other tooling systems can be coupled to and/or within the reconfigurablegantry tool system for performing additional operations.

The sine plate is rotatably and slidably coupled to the platform, andpreferably rotates from a horizontal zero degree position to a vertical90 degree position and translates along the platform. The gantry frameis slidably coupled to the platform. The robotic tool is movably coupledto the gantry frame and has a multi-axis range of motion. A workpiece issecured to the sine plate by the reconfigurable holding mechanism. Aplurality of workpieces can be clamped together and coupled to thereconfigurable holding mechanism.

The multi-axis numerically controlled robotic tool has proximity sensorsfor precisely locating and positioning the tool within and around theworkpiece. The tool can therefore perform numerous tooling operations onthe workpiece. The proximity sensors precisely locate and align the toolwith the workpiece before tooling operations are performed on theworkpiece. In addition, the platform can have a self leveling systemwith a configurable memory, such as the self leveling system disclosedand described in U.S. Pat. No. 5,587,900, issued on Dec. 24, 1996 toBullen, entitled SELF LEVELING INDEPENDENTLY PROGRAMMABLE SYSTEM, theteachings of which are incorporated herein by reference. As such,precision tooling operations can be performed on the workpiece.

The self leveling system senses and changes the inclination of theplatform. The self leveling device includes a lifting device affixedunder a horizontal member, a level sensing device affixed to the memberfor sensing an inclination of the member, a computer for inputing adesired orientation of the manufacturing plane with respect to thehorizon, a device for comparing the sensed inclination of the horizontalmember with the desired orientation, a device for computing a change inthe sensed inclination to achieve the desired orientation, and a deviceto transmit a control signal proportional to the change to the liftingdevice for achieving the desired orientation of the manufacturing plane.

A feature of the present invention is its reconfigurability. Anotherfeature of the present invention is its ability to precisely locate andperform tooling operations. Another feature of the present invention isits ability to assemble parts without a fixed jig assembly. Yet anotherfeature of the present invention is its self leveling mechanism withconfigurable memory.

An advantage of the present invention is that it eliminates the need forcostly tool families. Another advantage of the present invention is thatit increases the speed with which a part can be assembled, or implementengineering changes to an existing workpiece design with reduced costs.Yet another advantage of the present invention is its ability to performrepetitive tooling operations with reconfiguration.

The foregoing and still further features and advantages of the presentinvention as well as a more complete understanding thereof will be madeapparent from a study of the following detailed description of theinvention in connection with the accompanying drawings and appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIG. 1A is a perspective view of a prior art mold used to fabricate adrill positioning bonnet;

FIG. 1B is a perspective view of a prior art mold used to fabricate adrill positioning bonnet;

FIG. 2A is a perspective view of the mobile positioning system of thepresent invention;

FIG. 2B is a perspective view detailing the robotic tool of the mobilepositioning system of the present invention;

FIG. 3 is a perspective view of a portion of the system of FIG. 2Bshowing a translation module;

FIG. 4 is a perspective view of a portion of a second embodiment of thesystem of FIG. 2B showing a ballrail and pad assembly;

FIG. 5 is a perspective view illustrating the interaction of the sineplate with the tool of the present invention;

FIG. 6 is a block diagram of a control means for the system of FIG. 2A.

FIG. 7 is a perspective view illustrating the interaction of one toolcoupled to another tool of the present invention;

FIG. 8 is an assembly flow diagram illustrating the assembly of a part;and

FIG. 9 is a perspective view of an assembly line utilizing thereconfigurable tool of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following description of the preferred embodiment, reference ismade to the accompanying drawings which form a part hereof, and in whichis shown by way of illustration a specific embodiment in which theinvention may be practiced. It is to be understood that otherembodiments may be utilized and structural changes may be made withoutdeparting from the scope of the present invention.

Overview

FIG. 2A is a perspective view of the reconfigurable gantry tool of thepresent invention. The reconfigurable gantry tool 200 of the presentinvention includes a platform 202 for supporting a reconfigurableholding mechanism 204, a workpiece 206 coupled to the reconfigurableholding mechanism 204, a multi-axis numerically controlled robotic tool208 coupled to a gantry frame 210, a multi-movement control 212 devicecoupled to the tool 200, and a rotatable and translatable sine plate214.

In addition, the platform 202 can have a self leveling system 216 with aconfigurable memory, such as the self leveling system disclosed anddescribed in U.S. Pat. No. 5,587,900, issued on Dec. 24, 1996 to Bullen,entitled SELF LEVELING INDEPENDENTLY PROGRAMMABLE SYSTEM, the teachingsof which are incorporated herein by reference. As such, precisiontooling operations can be performed on the workpiece.

The self leveling system 216 senses and changes the inclination of theplatform 202. The self leveling device 216 includes a lifting device 218affixed under a horizontal member 220, a level sensing device 221affixed to the horizontal member 220 for sensing an inclination of thehorizontal member 220, a computer 212 for inputing a desired orientationof the manufacturing plane with respect to the horizon, a device forcomparing the sensed inclination of the horizontal member 220 with thedesired orientation, a device for computing a change in the sensedinclination to achieve the desired orientation, and a device to transmita control signal proportional to the change to the lifting device 218for achieving the desired orientation of the manufacturing plane.

The reconfigurable gantry tool 200 has a longitudinal translation module222 positioned parallel to an Y axis. The function and construction ofthe longitudinal translation module 222 are similar to other translationmodules used in the invention for transverse and vertical movement asexplained below. The longitudinal translation module 222 is slidablycoupled to the platform 202 and translates along the Y axis.

Movement of the longitudinal translation module 222 along the Y axis canbe achieved, for example, by having dual longitudinal translationmodules 222 engaged in corresponding translation rails 224. Any suitablearrangement for allowing the longitudinal translation module 222 totranslate along the Y axis can be used, such as a carriage belt/drivearrangement 226 with synchronized servo motors 230 controlled by thecontroller 212. Also, the longitudinal translation module 222 ispreferably removably attached to the platform 202 to allow tool 208 orframe 210 cleaning or other maintenance. The module 222 translates alongrails 224 in response to servo motors 230, by control means describedbelow.

The reconfigurable gantry tool 200 additionally includes a robotic arm231 coupled to a transverse translation module 232 and having a verticaltranslation module 234. The robotic arm 231 is coupled to the transversetranslation module 232 on one end and to the robotic tool 208 at anotherend. The robotic tool 208 can be any suitable tool, such as a drill,sealer, countersinker, etc., for performing tooling operations on theworkpiece. In addition, vacuum cleaners 235 can be located near the tool208 for accumulating waste from the tooling operation.

The transverse translation module 232 is preferably parallel to the Xaxis. The vertical translation module 234 is preferably parallel to theZ axis. The robotic arm 231 is slidably coupled to the transversetranslation module 232. This arrangement facilitates transverse movementalong the X axis. The vertical translation module 234 is slidablycoupled to the robotic arm 231. This arrangement facilitates verticalmovement along the Z axis. Both modules are driven by respective servomotors 236. The motors 236 may be connected to the modules 232, 234either by a belt reduction drive 238, gear drive, or a direct.

The gantry frame 210 and all the translation modules 222, 232, 234 alsoinclude linear sensors 240 located along a length of the respectiveframe or module. The sensors 240 are feedback sensors, such as lasersensors, glass scales or digital strips (discussed below in detail).Glass scales or digital strips generally have a length of approximatelythe same length as the frame or translation module on which it ismounted.

In a preferred embodiment, the longitudinal translation module 222comprises dual support bridge members 223. Bridge members 223 supportthe transverse translation module 232, parallel to the X axis and drivenby a servo motor 230. This combined structure forms a bridge over thework envelope with longitudinal translation modules 222 on either sideof the bridge. The motor 230 is connected to the longitudinaltranslation module 222 either by a belt reduction drive, gear drive, ora direct drive.

Referring to FIG. 2B along with FIG. 2A, the robotic tool 208 ispreferably a multi-axis computer numerical controlled (CNC) gantry forperforming specific tasks on the workpiece 206. The robotic tool 208preferably has proximity sensors 241 for precisely locating andpositioning the tool 208 within and around the workpiece 206. The tool208 can therefore perform numerous precise tooling operations on theworkpiece 206. The proximity sensors 241 precisely locate and align thetool 208 with and/or within the workpiece 206 before tooling operationsare performed on the workpiece 206. Also, this arrangement allows thetool 208 to be an inspection device.

In addition, the robotic tool 208 can include dual sub-modules 242 andsliding pads 244 driven by a single servo motor 250. Dual sub-modules242 provide additional strength to support and prevent back pressurefrom a machining operation from displacing the structure, which couldcause machining errors. The dual sub-modules 242 also include sensors240 along their length. Again, the motor 250 may be connected to thesub-modules 242 either by a belt reduction drive 238, 280, gear drive,or a direct drive. The belt reduction drives 238, 280 or gear drivesprovide increased accuracy in translational movement of the sliding pads244.

The sub-modules 242 translate a carriage 255 on which a rotation motor260 is mounted in order to rotate a machine tool 265 around an A axis.In accordance with one preferred embodiment of the invention, themachine tool 265 will be an electric drill for forming apertures in theworkpiece. A pivot motor 270 is also mounted on the carriage 255 and thepivot motor rotates the machine tool 265 along all axes, depending onthe position of the rotation motor 260. Rotational sensors 272 aremounted on each of the rotational motor 260 and pivot motor 270 tomeasure the angular rotation of the motors. As a result, rotation aboutthe A, B, and W axes are achieved.

Further, the vertical arrangement of robotic arm 231 provides theability of the tool 208 to perform tooling operations inside closedmembers. For example, tooling operations can be performed within ducts,which are one of the most difficult areas to perform tooling operationson when building an aircraft. Also, the vertical arrangement of the arm231, instead of a horizontal arrangement, eliminates arm deflectionsthat work against, rather than with, gravity.

FIG. 3 is a perspective view of a portion of the system of FIG. 2Bshowing a translation module. The translation modules 222, 232, and 234can use conventional ballscrew drive construction, which providesaccurate control at a minimum cost. As shown in FIG. 3, each module 222,232, and 234 consists of guide rails 300 and a ball lead screw 310mounted in a parallel position between the rails 300. The ball leadscrew 310 is supported at both ends of the module by bearings 315, whichare mounted on a support plate 305 that also supports the rails 300.

The pad 244 includes a threaded guide 320 which is positioned adjacentand between the rails 300 and engages the screw 310. As the screw 310turns, the sliding pad 244 translates along the rails 300. The screw 310can be coupled directly to a servo motor, such as the motor 236 in FIG.2B, or by means of the belt reduction drives 238, 280 or gear drives.

FIG. 4 is a perspective view of a portion of a second embodiment of thesystem of FIG. 2B showing a ballrail and pad assembly. In thisembodiment of the invention, a ballrail 400 is mounted near the module232 and is parallel to the transverse module 232. Further, the ballrail400 is positioned on the opposite side of the module 232 from thetransverse translation module 234 and is connected to the transversetranslation module by a modified sliding pad 405, which translates alongthe module 232 in a manner identical to sliding pad 244 (shown in FIG.2B). The pad 405 is operatively connected to the ballrail 400 at asemicircle 410 whose ballrail facing surface is covered with ballbearings 415. The ballrail 400 and pad 405 assembly (a "ballrail and padassembly") allows translation along the Z axis, but prevents motion ofthe pad 405 is the X direction.

The advantage of this ballrail and pad assembly is to offset the leverarm produced by the transverse translation module 234 about the module232, thus improving stability of the machine tool 265 (shown in FIG. 2B)during machine operations. For example during a drilling operation, aresistance force ("drill-back") may develop that can displace the drilland reduce the hole accuracy. The effect of drill-back is substantiallyreduced by the ballrail and pad assembly.

Referring back to FIG. 2A, the preferred self leveling system 216 of thepresent invention is similar (differences discussed below) in principleand in operation to the self leveling system disclosed and described inU.S. Pat. No. 5,587,900, issued on Dec. 24, 1996 to Bullen, entitledSELF LEVELING INDEPENDENTLY PROGRAMMABLE SYSTEM, the teachings of whichare incorporated herein by reference.

The preferred leveling system 216 of the reconfigurable tool 202comprises an adjusting mechanism, such as flat stands, lifting devices218, such as jacks, a horizontal member 220, a level sensing device 221affixed to the member 220 for sensing an inclination of the member 220,and a computer module as part of controller 212 for inputing a desiredorientation of the manufacturing plane with respect to the horizon. Eachadjusting mechanism is preferably affixed to a respective jack 218, eachof which are preferably affixed to the member 220.

Sensor cables (not shown) and lifting device cables (not shown) connectthe sensors and lifting devices, respectively, to the controller 212. Asuitable comparing device (not shown) compares the sensed inclination ofthe horizontal member 220 with the desired orientation and anotherdevice (not shown) computes changes in the sensed inclination to achievea desired orientation. Also, another device (not shown) transmits acontrol signal proportional to the change to the lifting devices 218 forachieving the desired orientation of the manufacturing plane.

The leveling system 216 is a multi function system. For instance, someof the functional attributes of the system include the ability to storein memory location heights of different support assemblies. Thisfacilitates quick and precise attachment to a certain support assemblyduring mobile transport from one support assembly to another. Also, theleveling system 216 has dormant storage leveling capabilities. Thisfunction allows storage of certain location heights in memory, therebypreventing racking of the system frame from storage on uneven surfaces.

Referring to FIG. 5 along with FIG. 2A, the workpiece 206 is secured tothe sine plate 214 by the reconfigurable holding mechanism 204. Anysuitable reconfigurable holding means, preferably with datum planelocators, such as high precision adjustable clamps or high precisionpneumatic suction devices can be used as the reconfigurable holdingmechanism 204. A single workpiece 206 can be secured to the platform 202or multiple workpieces can secured together first and then secured tothe platform. For example, a plurality of workpieces can be firstclamped together and then secured pneumatically to the platform by thereconfigurable holding mechanism 204.

The sine plate 214 is rotatably and slidably coupled to the platform202. The sine plate 214 preferably rotates from a horizontal zero degreeposition to a vertical 90 degree position. Any suitable means, such as arotatable joint, can be used to allow rotation of the sine plate 214.FIG. 2A illustrates the sine plate 214 at a horizontal position of zerodegrees while FIG. 5 illustrates the sine plate 214 at a verticalposition of 90 degrees. Also, the sine plate 214 of FIG. 2A istranslatable along the platform 202 about the Y axis. Any suitabledevice, such as linear actuators with encoders, can be used to allowslidability of the sine plate 214 along the Y axis.

Rotation of the sine plate 214 allows easy access to the workpiece 206from different angles. For instance, when the sine plate is at zerodegrees (FIG. 2A), a portion of the workpiece 206 faces the platform 202and is unaccessible. However, if the sine plate 214 is rotated to, forexample, 90 degrees, that same unaccessible portion of the workpiece isnow easily accessible. In addition, as will be discussed below indetail, rotation and translation of the sine plate 214 provides easymating of connecting workpieces or transferability of the workpiece toother reconfigurable tools or other locations.

Operation

FIG. 6 is a block diagram of a controller for the system of FIGS. 2A and2B. The reconfigurable tool 200 of FIG. 2A can be controlled by acontroller 500 comprised of a tool computer numerical control (CNC)device 501 and a platform CNC device 502, respectively, as illustratedin FIG. 6.

For the tool computer numerical control (CNC) device 501, a conventionalservo control module 504 sends translation signals 506 to the motors230, 236, and 250 (shown in FIG. 2B), rotation signals 508 to the motors260 and 270 (shown in FIG. 2B) and operation signals 510 to the machinetool 265 (shown in FIG. 2B). The module 504 receives sensor signals 512from the linear sensors 240, rotational sensors 272, and locator sensors241 (shown in FIG. 2B).

The sensor signals 512 measure the proximity of (a) the initialmachining part of the machine tool 265 (e.g. the tip of a drill) to adesired set of X, Y and Z coordinates (referred to as the "vector"), (b)the orientation of the tool path (e.g. the drill centerline) to thecontour of the workpiece surface (referred to as the "normal") asdefined by rotation and pivot angles, and can also sense the locationand position of the workpiece with respect to the tool 208.

The module also receives task signals 514 from a conventional industrialcontroller 516, and sends task completion signals 518 to the controller516. The controller 516 generates the task signals 514 from a workpiecedatabase 520 that is sent to the controller 516. The workpiece database520 comprises a set of task signals 514 and defines the work to beperformed on workpiece, such as the location, orientation and depth ofholes.

As shown in FIG. 6 each task signal 514 defines a task to be performedon the workpiece and is generated by the controller 516. For example ifthe task is to drill a hole in the workpiece, a basic data item in thetask signal 514 would be the location of the drill tip, i.e. the vector,and is defined by X, Y, and Z coordinates in relation to a workpiecereference datum. Another data item is the normal, which is defined byangles about the rotation and pivot axes at a selected vector. Otherdata to be defined could include the speed of the drill, the feed rateat which the drill moves with respect to the workpiece, and the distancethat the drill is to travel (which determines the depth of the hole).

The controller 516 holds in memory each task signal 514 in the workpiecedatabase 520. This workpiece database 520 could be provided by acomputer aided design ("CAD") program defining a finished workpiece andcould be entered in the controller 516 by manual or magnetic means.

In addition, the controller 516 determines when a task signal 514 (e.g.comprising the vector, normal, drill rates and distance) is sent to thecontrol module 504. For example, the controller 516 could be programmedto send the task signal 514 to the module 504 only after a hole drilledpursuant to a previous task signal has been finished, i.e., a "whendone" command.

When a task signal 514 is sent to the control module 504, it sendstranslation signals 506 and rotation signals 508 to move the machinetool 265 (shown in FIG. 2B) to the desired vector and normal. If thedesired vector or normal of the task signal 514 is not reached by meansof the translation signals 506 or rotation signals 508, one or moresensor signals 512 proportional to the error in coordinates or angleswill be sent to the module 504. The module 504 then generatesappropriate revised translation signals 506 or rotation signals 508 inorder to make the correction in vector or normal. The translationsignals 506 and rotation signals 508 also include a velocity commandthat directs the speed of the motors 230, 236, and 250 (shown in FIG.2B) in order to control the time at which the desired vector will bereached.

After the desired position is reached, the module 504 sends theoperation signal 510 (i.e. the remaining information from the tasksignal 514) to accomplish the desired work. For example when a drillreaches a desired vector and normal, the module 504 sends to a drill theoperation signal 510, comprising a drill speed, drill feed rate, and adrill distance. After this operation signal 510 has been sent, module504 sends the completion signal 518 to the controller 516, which thensends a subsequent task signal 514 to the module 504 and the operationis repeated until all the tasks in the workpiece database 520 have beencompleted.

In a second preferred embodiment, the linear sensors 240 and rotationalsensors 272 (shown in FIG. 2B) are digital strip sensors. Digital stripsensors are cheaper and less expensive to use than conventional lasermeasuring means and do not adversely affect the performance of thesystem 200. This result can be a significant savings because lasersensors can cost as much as 20 percent of the overall cost of the system200.

This embodiment is achieved by using the digital strips as the sensorsto measure the vector of the machine tool 265 at maximum travelpositions of each translation module 222, 232 and 234 (shown in FIG.2B), and at several commanded intermediate positions. These vectors arecompared with the location signals 506 (shown in FIG. 6) sent to reacheach of the measured positions, and vector errors are determined foreach module. This set of vector errors is programmed into the memory ofthe controller 516. After this calibration procedure, when the workpiecedatabase 520 requires movement to a set of coordinates, the controller516 corrects the task signal 514 by the amount of the vector errors. Asimilar calibration procedure is used to measure normal errors and toeliminate the need for rotational sensors 272.

The self leveling system 216 of the platform 202 of FIG. 2A operates ina similar manner as the self leveling system disclosed and described inU.S. Pat. No. 5,587,900, issued on Dec. 24, 1996 to Bullen, entitledSELF LEVELING INDEPENDENTLY PROGRAMMABLE SYSTEM, the teachings of whichare incorporated herein by reference.

In a preferred embodiment, for platform control device 502, a platformcontrol module 600 sends operation signals 601, 602 to the sine plate214 and self leveling system 216 (shown in FIG. 2A), respectively. Themodule 600 also receives position and sensor signals 603, 604 from thesine plate 214 and self leveling system 216 (shown in FIG. 2A),respectively. The operation signals 601 provide rotation of the sineplate 214 between zero and 90 degrees. The operation signals 602 providemovement while the position and sensor signals provide specific positionand locations to precisely level the system.

Working Example

FIG. 7 is a perspective view illustrating the interaction of onereconfigurable tool of the present invention coupled to anotherreconfigurable tool of the present invention. In certain instances, itmay desirable to couple a first reconfigurable tool 620 to a secondreconfigurable tool 622. This configuration provides easy mating of afirst workpiece 624 of the first reconfigurable tool 620 to a secondworkpiece 626 second reconfigurable tool 622. Also, this configurationprovides easy transferability of the first workpiece 624 to the secondreconfigurable tool 622.

For example, for mating the first workpiece 624 with the secondworkpiece 626, the sine plate 628 of the first reconfigurable tool 620is initially translated along the platform 630 to an appropriateposition. Next, the sine plate 628 is rotated from zero to 90 degrees. Asine plate 632 of the second reconfigurable tool 622 is similarlytranslated along a platform 634 and rotated from to zero to 90 degrees.This provides the first and second workpieces 624, 626 in facingrelationship, thereby allowing mating of the workpieces 624, 626. Afterthe workpieces 624, 626 are properly mated, they can be easilytransferred to another location or tool or can have tooling operationsperformed on them by either or both reconfigurable tools 620, 622.

Non-matrix Assembly Line

For example purposes only, FIG. 8 illustrates an assembly flow diagramof only a section of an example aircraft. As illustrated, the assemblythe aircraft requires many subcomponents first connected together,second mated with other connected subcomponents, next mated with otherdifferent connected subcomponents, and so on.

As an example, first, bulkheads 801 are connected to form an aft ductstructure 802 and an aft center fuselage center barrel 804. Second, theaft duct structure 802 and the aft center fuselage center barrel 804 aremated together to form an aft center fuselage 806. Third, forward sidesurrounding panels 808 and a top panel 810 are connected to form aforward center fuselage 814. Fourth, aft fuselage panels 815 areconnected to an aft fuselage keel 816 and an aft fuselage nozzle 818 toform an aft fuselage mate 820. Fifth, inlet nacelles 822 are mated withthe aft fuselage mate 820 and with the forward center fuselage 814.These two products are mated together to form a center fuselage mate824. Sixth, vertical fins 826 and aft engine access doors 828 are matedwith the center fuselage mate 824 to form a sub system installation andvertical attach 830. Next, forward engine access doors 832 are matedwith the sub system installation and vertical attach 830 to form acenter aft fuselage final assembly 834.

Current methods of assembling the structure of FIG. 8 include using anon-reconfigurable, fixed, custom matrix. To create the large structure,large assembly jigs, large drill bonnets, drill tools, drill hoods areneeded. Workpieces are placed within the large assembly jigs. Next, workstands are elevated above the ground and are built around thisarrangement in order to work on the workpiece. As a result, a largecustom fixed matrix is produced with the expensive fixed assembly jigsas the building blocks of the structure.

Consequently, the devices and methods that comprises this technique arevery expensive, inefficient, and waste resources. The present inventionsolves this problem and is embodied in a new apparatus and method forassembling large structures similar to the one depicted in FIG. 8. Sucha structure can be assembled with the reconfigurable tool of FIGS. 2-7,as described below in FIG. 9, without expensive custom matrix devices.

FIG. 9 is a perspective view of an assembly line utilizing thereconfigurable tool of the present invention. A plurality ofreconfigurable gantry tools with extended platforms 944 and sine plates945 can be strategically coupled to one another to form a non-matrixassembly line. Further, other tooling systems 947 can be coupled toand/or within the reconfigurable gantry tool assembly line forperforming additional operations other than those performed by thereconfigurable gantry tools. With this novel arrangement of the presentinvention, a non-matrix, non-custom, repeatable, and reconfigurableassembly line is produced. As a result, the workpieces, comprising thecomponents and subcomponents of the final part to be built are thebuilding blocks, and not the custom fixed assembly jigs. Also, theworkpieces can be brought down to ground level and worked on at acomfortable location.

For example, as shown in FIG. 9, a first reconfigurable gantry tool 950can be used to perform a tooling operation on part A 952. A secondreconfigurable gantry tool 954 can be used to perform a toolingoperation on part B 956. The first reconfigurable gantry tool 950 can becoupled to the second reconfigurable gantry tool 954 for mating part A952 with part B 956 as part C 958. Similarly a third reconfigurablegantry tool 960 can be used to perform a tooling operation on part D962. A fourth reconfigurable gantry tool 964 can be used to perform atooling operation on part E 968. The third reconfigurable gantry tool960 can be coupled to the fourth reconfigurable gantry tool 964 formating part D 962 with part E 968 as part F 970.

The third and fourth reconfigurable gantry tools 960, 964 can performthe identical operation of the first and second reconfigurable gantrytools 950, 954 so that part C 958 and F 970 are identical parts. A sixthreconfigurable gantry tool 972 can be used to perform a toolingoperation on part H 974, which can be sent to a seventh reconfigurablegantry tool 976 or another tool for perform a tooling operation on partH 974. Part H 974 can then be either transferred to another assemblyline or mated with part C 958 and/or part F 970 via their respectivesine plates 945 as discussed above.

Alternatively, the first and second reconfigurable gantry tools 950, 954can perform different operations than the first and secondreconfigurable gantry tools 950, 954. In this case, a fifthreconfigurable gantry tool can be located between the first and secondand third and fourth reconfigurable gantry tools 950, 954, 960, 964 tomate part C 958 with part F 970 to form a new part, which can then bemated with part H 974, sent to tools 947 for other processing, sent toanother reconfigurable tool for mating with another part, or sent toanother location.

As can be seen from FIG. 9, many modifications to the assembly line canbe made by strategically combining reconfigurable gantry tools and othertools in order to assemble a product such as the one depicted in FIG. 8.

The foregoing description of the preferred embodiment of the inventionhas been presented for the purposes of illustration and description. Itis not intended to be exhaustive or to limit the invention to theprecise form disclosed. Many modifications and variations are possiblein light of the above teaching. It is intended that the scope of theinvention be limited not by this detailed description, but rather by theclaims appended hereto.

What is claimed is:
 1. A reconfigurable gantry tool for performingtooling operations on a workpiece, comprising:a movable platform; a sineplate rotatably and slidably coupled to said platform; a numericalcontrolled gantry slidably coupled to said platform to allow multi-axismovement of a toc supported by, said gantry for performing toolingoperations on said workpiece; and a multi-movement control devicecoupled to said platform, sine plate, and gantry for controllingmovement of said coupled devices.
 2. The system of claim 1, wherein saidreconfigurable gantry tool platform further includes a self leveler. 3.The system of claim 2, wherein said reconfigurable gantry tool is afirst reconfigurable gantry tool, wherein said system further comprisesa second reconfigurable gantry tool coupled to said first reconfigurablegantry tool for receiving said workpiece from said sine plate.
 4. Thesystem of claim 1, wherein said gantry further includes an automaticlocator for properly locating and aligning said gantry with a selectedlocation on said workpiece.
 5. The system of claim 1, wherein saidgantry comprises:a robotic arm having an end machine tool and a rotatorfor rotating said end machine tool about a rotational axis and a pivotorfor pivoting said end machine tool about any pivot axis orthogonal tosaid rotational axis; a vertical translation module coupled to saidrobotic arm and having a vertical movement device for translating saidrobotic arm along a Z axis; a plurality of longitudinal translationmodules coupled to said robotic arm and said platform and having alongitudinal movement device for translating said longitudinaltranslation modules along a y axis of said platform; and a transversetranslation module coupled to said robotic arm and said verticaltranslation module and having a transverse movement device fortranslating said transverse translation module along an X axis.
 6. Thesystem of claim 5 wherein each of said translation module furthercomprises:a rail for supporting each of said respective module; and alinear ballscrew threadedly engaged with each of said respective module.7. The system of claim 5 wherein each of said movement device of each ofsaid translation modules further comprises:a motor connected to each ofsaid respective translation module for moving each of said respectivemodule.
 8. The system of claim 7 further comprising:a belt reductiondrive connecting said motor to each of said respective translationmodule.
 9. The system of claim 5 wherein said vertical translationmodule further comprises:a secondary vertical translation module alignedparallel to said vertical translation module and connected to saidvertical movement device.
 10. The system of claim 5 wherein said controldevice comprises:a controller for storing control signals for each ofsaid respective movement device and for said machine tool, and sendingsaid control signals to each of said respective movement device and saidmachine tool at predetermined intervals.
 11. The system of claim 10wherein said control signals for each of said respective movement devicefurther comprise:a set of cartesian coordinates for each of saidrespective movement devices; and a set of angles for each of saidrotator and pivotor.
 12. The system of claim 11 wherein said controlsignals for said machine tool further comprise:a set of machine tooloperation instructions.
 13. The system of claim 5 wherein:each of saidtranslation modules, rotator, and pivotor further comprises a sensor formeasuring a position of each of said respective translation modules anda position of said machine tool about said rotational axis and saidpivot axis, and sending a position signal; a controller for storingcontrol signals for each of said respective movement device and for saidmachine tool, and sending said control signals; and a control module forreceiving each of said respective control signals, sending each of saidrespective control signals to each of said respective movement devicesand to said machine tool, receiving each of said respective sensorposition signals, and sending position correction signals to each ofsaid respective movement devices.
 14. The system of claim 5 furthercomprising:a ballrail mounted parallel to said transverse translationmodule on a side opposite to said vertical translation module; a slidingdevice connected to said transverse translation module and engaging saidballrail so as to constrain transverse movement of said transversetranslation module and to prevent vertical movement of said transversetranslation module.
 15. A reconfigurable gantry tool, comprising:amovable platform; a sine plate rotatably and slidably coupled to saidplatform; a reconfigurable holding device coupled to said sine plate forsecuring a workpiece; a gantry frame slidably coupled to said platform;a robotic arm slidably coupled to said gantry frame, said robotic armhaving a multi-axis numerical controlled tool for performing toolingoperations on said workpiece; and a multi-movement control devicecoupled to said platform, sine plate, gantry frame, and robotic arm forcontrolling movement of said coupled devices.
 16. The system of claim15, wherein said reconfigurable gantry tool further includes a selfleveler.
 17. The system of claim 16, wherein said self leveler is ahorizon leveling system.
 18. The system of claim 15, wherein said gantryfurther includes an automatic locator for properly locating and aligningsaid gantry with a selected location on said workpiece.
 19. The systemof claim 15, wherein said gantry frame comprises a vertical translationmodule coupled to said robotic arm and having a vertical movement devicefor translating said robotic arm along a Z axis, a plurality oflongitudinal translation modules coupled to said robotic arm and saidplatform and having a longitudinal movement device for translating saidlongitudinal translation modules along a y axis of said platform, and atransverse translation module coupled to said robotic arm and saidvertical translation module and having a transverse movement device fortranslating said transverse translation module along an X axis.
 20. Thesystem of claim 15, wherein said robotic arm has an end machine tool anda rotator for rotating said end machine tool about a rotational axis anda pivotor for pivoting said end machine tool about any pivot axisorthogonal to said rotational axis.
 21. The system of claim 15, whereinsaid reconfigurable gantry tool is a first reconfigurable gantry tool,wherein said system further comprises a second reconfigurable gantrytool coupled to said first reconfigurable gantry tool for receiving saidworkpiece from said sine plate.